A person is able to ...

A person is able to understand only when he solves the problem by himself.
 Peter Deunov

Quotes from the same author

If you wish to befriend someone, look for a person who loves first God then themselves. If they love God, they will be able to love their neighbor, too.
 Peter Deunov
Yours is only what you always have on you.
 Peter Deunov
Being happy is a great science. If you are not happy, do not be confused. Happiness is hard to achieve.
 Peter Deunov